CFD Analysis of Primary Air Flow Field of a Swirl Injector Using Embedded LES-Based Hybrid Model

Injector plays a pivotal role in meeting requirements of combustion performance in terms of combustion efficiency, flame stability, ignition, lower emissions, etc. In a multi-swirler injector configuration, air flow field inside injector is mainly dictated by primary swirler. Present CFD studies have been attempted to characterize flow field of a conical nozzle fitted with a radial swirler. Embedded LES-based hybrid model has been used where computational domain is divided into three zones which are seamlessly connected by capturing the interface fluid dynamics. In LES zone, both time and spatial scales have been resolved based on the results of a precursor RANS analysis. Analysis is carried out with CFL no. around 2, time step of 1 μs. The analysis is reasonably able to capture various unsteadiness (PVC, CTRZ, frequencies, TKE useful for the atomization of liquid fuel) which are not possible to be captured using URANS models.